This is one of the highest awards judged by the Iris Society of Australia (ISA). It is awarded by the British Iris Society in honor of William Rikatson Dykes. The ISA Judges Handbook (link now goes to Archive.org, retrieved 11/3/2020) describes the process used to choose winners on page 52: "The cultivar receiving the highest average score in the test gardens is awarded the Australian Dykes Medal. Since the Australian Dykes Medal gardens feature both bearded and beardless irises, the Iris Society of Australia (ISA) Medal is awarded annually for the top-scoring iris of a different type to that which has received the Dykes Medal, e.g. if the Dykes Medal winner is a bearded cultivar, then the highest-scoring beardless cultivar receives the ISA Medal, and vice versa."
See also: Iris Society of Australia Medal (page needs to be created).
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